Use of a dyestuff for ink jet printing recording materials

ABSTRACT

Disclosed are dyestuff mixtures for printing recording materials, especially textile fibre materials, paper and papery substrates and plastic films and plastic, as well as compositions suitable for ink-jet printing comprising a dyestuff of the formula (I)

The invention relates to novel dyestuff mixtures, the use of suchmixtures for printing recording materials, especially paper or paperysubstrates, textile fibre materials, plastic films and plastictransparencies by the inkjet printing process and also to the recordingmaterials printed thereby.

Inkjet printing processes are becoming more and more important forindustrial applications.

Inkjet printing processes are known. In what follows, the principle ofinkjet printing will only be discussed very briefly. Details of thistechnology are described for example in the Ink-Jet-Printing section ofR. W. Kenyon in “Chemistry and Technology of Printing and ImagingSystems”, Peter Gregory (editor), Blackie Academic & Professional,Chapmann & Hall 1996, pages 113-138, and references cited therein.

In the inkjet printing process, individual droplets of the ink aresprayed from a nozzle onto a substrate in a controlled manner. Thecontinuous inkjet method and the drop-on-demand method are employedpredominantly for this purpose. In the case of the continuous inkjetmethod, the droplets are produced continuously and droplets not neededfor printing are diverted into a collecting vessel and recycled. In thecase of the discontinuous drop-on-demand method, by contrast, dropletsare generated and printed as desired, i.e. droplets are only generatedwhen this is necessary for printing. The droplets may be generated forexample by means of a piezo inkjet head or by means of thermal energy(bubble jet).

By additionally disposing at least one nozzle with yellow, magenta orcyan ink side by side it is possible to obtain colour reproductions inhigh quality. This process is known as polychromatic printing or, whenthree colour components are used, as trichromatic printing.

The composition of the invention can be used with all known and suitableinkjet printers for printing paper or papery substrates, textile fibrematerials, plastic films and plastic transparencies. This applies notonly to the use in monochromatic printing but also to polychromaticprinting, especially trichromatic printing.

The composition of the ink for the inkjet printing process has topossess a suitable conductivity, sterility in storage, viscosity andsurface tension to meet the specific requirements of inkjet ink. Inaddition, the prints on the recording materials have to have goodproperties and fastness.

Useful recording materials, as mentioned above, are preferably paper andpapery substrates, textile fibre materials, plastic films and plastictransparencies. But glass and metal may be used as well.

Useful papers or papery substrates include all known such materials.Preference is given to papers or papery substrates coated on at leastone side with a material which is particularly receptive to inkcompositions. Such papers or papery materials are described inter aliain DE 3018342, DE 4446551, EP 164196 and EP 875393.

Useful textile fibre materials are in particular hydroxyl-containingfibre materials. Preference is given to cellulosic fibre materials,which consist of or comprise cellulose. Examples are natural fibrematerials such as cotton, linen or hemp and regenerated fibre materialssuch as, for example, viscose and also lyocell.

Useful plastic films or plastic transparencies include all known suchmaterials. Preference is given to plastic films or plastictransparencies coated on at least one side with a material which isparticularly receptive to the ink compositions. Such plastic films orplastic transparencies are described inter alia in EP 755332, U.S. Pat.Nos. 4,935,307, 4,956,320, 5,134,198 and 5,219,928.

This invention provides a inkjet printing composition for printingrecording materials by comprising

-   -   1) the dye of formula (I)        and    -   2) water or a medium including a mixture of water and an organic        solvent, an anhydrous organic solvent or a solid having a low        melting point,

There may be optionally further additives be present in the compositionaccording to the invention as described below.

The invention further provides the use of a compound of formula (I)

for ink jet printing or the use of a compound of formula (I) in ink jetprinting compositions. The invention further provides the use of acompound of formula (I) for ink jet printing or for electrophotographicprinting. The invention further provides toners for electrophotographicprinting comprising a compound of formula (I).

This invention further provides dyestuff mixtures comprising at leastcompound of formula (I)

as free acid or in salt form and at least one compound according toformula (II) and/or formula (III) and/or formula (IV) and/or formula (V)wherein the compounds of formulas (II) signifies

wherein

-   -   R₇ and R′₇ signify independently from each other H or halogen,    -   R₈ signifies —OH or NR₁₆R₁₇, wherein        -   R₁₆ signifies H; unsubstituted C₁₋₄alkyl; substituted            C₁₋₄alkyl; unsubstituted phenyl or a substituted phenyl,        -   R₁₇ signifies unsubstituted C₁₋₄alkyl; substituted            C₁₋₄alkyl;    -   unsubstituted phenyl or a substituted phenyl,    -   R₉ signifies O or NR₁₇, wherein        -   R₁₇ has the same meanings as defined above,    -   R₁₀ and R′₁₀ signify independently from each other H; halogen;        unsubstituted C₁₋₂alkyl or —NO₂,    -   R₁₁, signifies —SO₃H or —COOH,    -   R₁₂ signifies H or halogen,    -   R₁₃ signifies H; —SO₃H or halogen    -   R₁₄ signifies H or halogen,    -   R₁₅ signifies H or halogen,        wherein the compounds of formulas (III) signifies        wherein    -   R₁₈ signifies H; —COC₁₋₂alkyl; —CO(CH₂O)_(n)—R₂₂; —SO₂R₂₂,        -   wherein        -   R₂₂ signifies an unsubstituted phenyl or a phenyl moiety,            which is substituted by at least one substituent of the            group consisting of —CH₃ or halogen,        -   n is 0 or 1,    -   R₁₉ signifies H; —CH₃; —SO₃H or —OR₂₃, wherein        -   R₂₃ signifies —CH₃; unsubstituted phenyl; substituted phenyl            or benzyl    -   R₂₀ signifies H; halogen; C₁₋₁₀alkyl or —NHCOCHBrCH₂Br    -   R₂₁ signifies H; —NO₂; C₁₋₁₅alkyl or C₅₋₇cycloalkyl;        wherein the compounds of formulas (IV) signifies        wherein    -   R₂₄ signifies H or —SO₃H,    -   R₂₅ signifies H; —NHCOC₁₋₂alkyl or —OH,    -   R₂₆ signifies H or —OH;    -   R₂₇ signifies        wherein    -   R₂₈ signifies H or unsubstituted phenyl,    -   R₂₉ signifies H; —COH; —NO₂;        wherein    -   R₃₀ is H or —CH₃, or    -   R₂₇ signifies        wherein the compounds of formulas (V) signifies        wherein    -   R₃₁ signifies H or    -   R₃₂ signifies        wherein    -   R₃₃ signifies H; —SO₃H; —CF₃; —Cl; —COOC₁₋₂alkyl; —SO₂R₃₆,        wherein        -   R₃₆ signifies unsubstituted phenyl; substituted phenyl;            O-phenyl; —NH-C₁₋₂alkyl; —N(C₁₋₆alkyl)₂; unsubstituted            C₅₋₈cycloalkyl; substituted C₅₋₈cycloalkyl; C₅₋₈cycloalkyl            with at least one N, O            -   or S atom incorporated into the ring;    -   R₃₄ signifies H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl        ring can be unsubstituted or substituted;        —N(C₁₋₂alkyl)COC₁₋₄alkyl; —N(C₁₋₂alkyl)COphenyl, wherein the        phenyl ring can be unsubstituted or substituted; unsubstituted        phenyl; substituted phenyl; O-phenyl, wherein the phenyl can be        unsubstituted or substituted; halogen; —SO₃H; —NHCOOC₁₋₂alkyl;        —NHCOOC₅₋₇cycloalkyl, wherein the cycloalkyl can be substituted        or unsubstituted and —SO₂NHphenyl, wherein the phenyl ring can        be unsubstituted or substituted,    -   R₃₅ signifies H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl        ring can be unsubstituted or substituted;        —N(C₁₋₂alkyl)COC₁₋₄alkyl; —N(C₁₋₂alkyl)COphenyl, wherein the        phenyl ring can be unsubstituted or substituted; unsubstituted        phenyl; substituted phenyl; O-phenyl, wherein the phenyl can be        unsubstituted or substituted; halogen; —Cl; —CH₃; —COOC₁₋₄alkyl        and —SO₂NHphenyl, wherein the phenyl ring can be unsubstituted        or substituted.

Any alkyl or alkylene group may be linear or branched.

Useful cations for salt formation include in particular alkali metal,alkaline earth metal as well ammonium cations. Examples of such cationsare alkali metal cations, for example potassium, lithium or sodium ionsand ammonium cations, e.g. mono-, di-, tri- or tetra-methyl ammoniumcations or mono-, di-, tri- or tetra-ethyl ammonium cations or mono-,di- or tri-ethanol ammonium cations. The cations may be the same ordifferent, i.e. the compounds may be in mixed salt-form.

Preferred compounds according to formula (II) are C.I. (Colour Index)Acid Red 50, C.I. Acid Red 51, C.I. Acid Red 52, C.I. Acid Red 87, C.I.Acid Red 91, C.I. Acid Red 92, C.I. Acid Red 93, C.I. Acid Red 94, C.I.Acid Red 95, C.I. Acid Red 98, C.I. Acid Red 289, C.I. Acid Violet 9 orC.I. Acid Violet 30 and

-   preferred compounds according to formula (III) are C.I. Acid Red 1,    C.I. Acid Red 33, C.I. Acid Red 35, C.I. Acid Red 40, C.I. Acid Red    76, C.I. Acid Red 106, C.I. Acid Red 138, C.I. Acid Red 155, C.I.    Acid Red 160, C.I. Acid Red 172, C.I. Acid Red 0.249, C.I. Acid Red    264 or C.I. Acid Red 265, and-   preferred compounds according to formula (IV) are C.I. Acid Red 15,    C.I. Acid Red 19, C.I. Acid Red 29, C.I. Acid Red 60, C.I. Acid Red    68, C.I. Acid Red 154 or C.I. Acid Red 176 and-   preferred compounds according to formula (V) are C.I. Acid Red 30,    C.I. Acid Red 34, C.I. Acid Red 37, C.I. Acid Red 42, C.I. Acid Red    54, C.I. Acid Red 57, C.I. Acid Red 231, C.I. Acid Red 266, C.I.    Acid Red 301 or C.I. Acid Red 337

Especially preferred mixture comprises a compound according to formula(Ie) and C.I. Acid Red 52 and/or C.I. Acid Red 289 which have thefollowing formulae

respectively.

It is possible to use the dyestuff (I) without any further dyestuff inthe composition Ink jet printing compositions according the presentinvention.

A further embodiment of the present invention relates to a compositionfor printing recording materials, preferably paper and paperysubstrates, textile fibre materials, plastic films and plastictransparencies by the inkjet printing process, comprising

-   1) the dye of the formula (I) as defined above and-   2) water or a medium including a mixture of water and an organic    solvent, an anhydrous organic solvent or a solid having a low    melting point,-   The inkjet printing composition may optionally comprise further    additives.

A further embodiment of the present invention relates to a inkjetprinting composition for printing recording materials, preferably paperand papery substrates, textile fibre materials, plastic films andplastic transparencies, comprising

-   1) a mixture of dyestuffs as defined above and-   2) water or a medium including a mixture of water and an organic    solvent, an anhydrous organic solvent or a solid having a low    melting point,-   The inkjet printing composition may optionally comprise further    additives.

When dyestuff mixture are used a dyestuff mixture according to thepresent invention preferably comprises

-   50-99 wt-% of at least one compound according to formula (I) and-   1-50 wt-% of at least one compound according to formula (II) and/or    at least one compound according to formula (III) and/or at least one    compound according to formula (IV) and/or at least one compound    according to formula (V).

The weight percentages are related to the total amount of dyestuff andwherein the sum of the weight percentages is always 100.

A further embodiment of the invention relates to the use of the abovementioned compositions for the ink-jet printing process.

The dyes of the formula (I), (II), (III), (IV) and/or (V) in the used inthe inks should preferably be low in salt, i.e. have a total saltcontent of less than 0.5% by weight, based on the weight of the dyes.Dyes having higher salt contents (owing to their preparation and/or thesubsequent addition of extenders) may be desalted, for example by meansof membrane separation processes, such as ultrafiltration, reverseosmosis or dialysis.

The inks preferably include a total amount of dyes which is in the rangefrom 0.5 to 35% by weight, preferably in the range from 1 to 35% byweight, more preferably in the range from 2 to 30% by weight, mostpreferably in the range from 2.5 to 20% by weight, based on the totalweight of the ink.

The inks include 99.5-65% by weight, preferably 99-65% by weight, morepreferably 98-70% by weight, most preferably 97.5-80% by weight, of anabove-mentioned medium 2), which includes a mixture of water and anorganic solvent, an anhydrous organic solvent or a solid having a lowmelting point.

When said medium 2) is a mixture including water and an organic solventor an anhydrous organic solvent, the dye mixtures comprising at leastone compounds of formula (I) and at least one compound of formula (II)and/or at least one compounds of formula (III) and/or at least onecompound of formula (IV) and/or at least one compound of formula (V) arepreferably completely dissolved in this medium.

Preferably the dye mixtures comprising at least one compounds of formula(I) and at least one compound of formula (II) and/or at least onecompounds of formula (III) and/or at least one compound of formula (IV)and/or at least one compound of formula (V) as well as the new compoundsaccording to formula (I) have a solubility of not less than 2.5% byweight in this medium 2) at 20° C.

When the ink composition of the invention is used for printing paper orpapery substrates, the inks are preferably used together with thefollowing compositions.

When the medium is a mixture of water and an organic solvent, the weightratio of water to organic solvent is preferably in the range from 99:1to 1:99, more preferably in the range from 99:1 to 50:50, particularlypreferably in the range from 95:5 to 80:20.

It is preferable for the organic solvent, which is included in themixture with water to be a water-soluble solvent or a mixture of variouswater-soluble solvents. Preferred water-soluble organic solvents areC₁₋₆-alcohols, preferably methanol, ethanol, n-propanol, isopropanol,n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol andcyclohexanol; linear amides, preferably dimethylformamide, ordimethylacetamide; ketones and keto alcohols, preferably acetone, methylethyl ketone, cyclohexanone and diacetone alcohol; water-miscibleethers, preferably tetrahydrofuran and dioxane; diols, preferably diolspossessing 2 to 12 carbon atoms, e.g. 1,5-pentanediol, ethylene glycol,propylene glycol, butylene glycol, pentylene glycol, hexylene glycol andthiodiglycol and oligo- and poly-alkylene glycols, preferably diethyleneglycol, triethylene glycol, 1,2-propylenglycol, polyethylene glycol andpolypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol;mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers ofdiols possessing 2 to 12 carbon atoms, particularly preferably2-methoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol,2-[2-(2-methoxyethoxy)ethoxy]-ethanol,2-[2-(2-ethoxyethoxy)ethoxy]ethanol, diethylenglycol-mono-n-butylether,ethylene glycol monoallyl ether and polyoxyethylenalkylether (forexample Emulgen 66 of KAO Corp. (Emulgen is a trade mark of the KaoCorp.)); alkanolamines, preferably 2-diethylamine-1-ethanol,3-dimethylamine-1-propanol, 3-diethylamine-1-propanol,2-(2-aminoethoxy)ethanol, 2-(2-dimethylaminoethoxy)-ethanol,2-(2-diethylaminoethoxy)ethanol, mono-, di-, triethanolamine,monoglycolamines and polyglycolamines, which may be obtained by reactionof ammonia, alkyl- or hydroxyalkylamines like methylamine, ethylamine,dimethylaamine, diethylamine, mono-, di- and triethanolamines withalkyleneoxides for example ethylenoxide, 1,2-propylenoxide,1,2-butylenoxide or 2,3-butylenoxide in suitable ratios as described inDE2061760A, preferably diethylenglycolamine, triethylenglycolamin,Bis-diethylenglycolamin, polyoxyethylen-(6)-triethanolamine,polyoxyethylen-(9)-triethanolamine, o-(2-aminoethyl)-polyethylenglycol750, o,o-Bis-(2-aminopropyl)-polyethylenglycol 500, 800, 1900, 2000,o,o′-Bis-(3-aminopropyl)-polyethylenglycol 1500, cyclic amides,preferably 2-pyrrolidone, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone,N-(2-hydroxy)ethyl-2-pyrrolidone, caprolactam and1,3-dimethylimidazolidone; cyclic esters, preferably caprolactone;sulphoxides, preferably dimethyl sulphoxide and sulpholane.

In a preferred composition, the medium as per 2) includes water and atleast 2 or more, more preferably 2 to 8, water-soluble organic solvents.

Particularly preferred water-soluble solvents are cyclic amides,particularly 2-pyrrolidone, N-methyl-2-pyrrolidone andN-ethyl-2-pyrrolidone; N-(2-hydroxy)ethyl-2-pyrrolidone, C₁₋₆-alcohols,preferably n-propanol, cyclohexanol, diols, preferably 1,5-pentanediol,ethylene glycol, thiodiglycol, diethylene glycol, triethylene glycol and1,2-propyleneglycol, triols, preferably glycerol; and mono-C₁₋₄-alkyland C₁₋₄-alkyl ethers of diols, more preferably mono-C₁₋₄-alkyl ethersof diols possessing 2 to 12 carbon atoms, particularly preferably2-[2-(2-methoxyethoxy)-ethoxy]-ethanol,diethylenglycol-mono-n-butylether, (for example Emulgen 66 of KAO Corp.(Emulgen is a trade mark of the Kao Corp.)), 2-diethylamine-1-ethanol,3-dimethylamine-1-propanol, 3-diethylamine-1-propanol,2-(2-diethylaminoethoxy)-ethanol, triethanolamine, diethylenglycolamin,polyglycolamines, preferably polyoyxethylen-(6)-triethanolamin,polyoxyethylen-(9)-triethanolamine, o-(2-aminoethyl)-polyethylen 750,o,o-bis-(2-aminopropyl)-poyethylen 500 ando,o-bis-(3-aminopropyl)-polyethylenglycol 1500.

A preferred medium as per 2) comprises

-   -   (a) 75 to 95 parts by weight of water and    -   (b) 25 to 5 parts of one or more of the watersoluble solvents.        wherein the parts are by weight and all parts of (a) and (b) add        up to 100.

Examples of further useful ink compositions including water and one ormore organic solvents are found in the Patent Specifications U.S. Pat.Nos. 4,963,189, 4,703,113, 4,626,284 and EP 425150A.

When the medium as per 2) includes an anhydrous (i.e. less than 1% byweight of water) organic solvent, this solvent will have a boiling pointof 30 to 200° C., more preferably of 40-150° C., particularly preferablyof 50-125° C.

The organic solvent can be water-insoluble, water-soluble or mixtures ofsuch solvents.

Preferred water-soluble organic solvents are all above-describedwater-soluble organic solvents and mixtures thereof.

Preferred water-insoluble solvents include inter alia aliphatichydrocarbons; esters, preferably ethyl acetate; chlorinatedhydrocarbons, preferably CH₂Cl₂; and ethers, preferably diethyl ether;and mixtures thereof.

When the liquid medium as per 2) includes a water-insoluble organicsolvent, it is preferable to add a polar solvent to increase thesolubility of the dye in the liquid medium.

Examples of such polar solvents are C₁₋₄-alcohols, preferably ethanol orpropanol; ketones, preferably methyl ethyl ketone.

The anhydrous organic solvent can consist of a single solvent or amixture of 2 or more different solvents.

When it is a mixture of different solvents, a mixture including 2 to 5different anhydrous solvents is preferred. This makes it possible toprovide a medium as per 2) which permits good control of the dryingproperties and of the stability of the ink composition in storage.

Ink compositions including an anhydrous organic solvent or mixturesthereof are of particular interest when rapid drying times are requiredand especially when they are used for prints on hydrophobic andnon-absorbing substrates, such as plastic, metal and glass.

Preferred low-melting media have a melting point of 60 to 125° C. Usefullow-melting solids include long-chain fatty acids or alcohols,preferably those having a C₁₈₋₂₄-carbon chain, and sulphonamides.

The ink composition of the invention may further include as auxiliariesadditional components which are normally used in inkjet inks, forexample viscosity improvers, surface tension improvers, biocides,corrosion inhibitors, levelling agents, drying agents, humefactants, inkpenetration additives, light stabilizers, UV absorbers, opticalbrighteners, coagulation reducers, ionic or nonionic surfactants,conducting salts and pH buffers.

These auxiliaries are preferably added in an amount of 0-5% by weight.

To prevent precipitation in the ink compositions of the invention, thedyes used have to be purified clean. This can be done with commonlyknown purifying methods.

When printing textile fibre materials, useful additives, as well as thesolvents, include water-soluble nonionic cellulose ethers or alginates.

The preferred material is paper. The paper may be plain or treated.

Preference is given to ink compositions having a viscosity of 1 to 40mPa·s, especially 5 to 40 mPa·s, preferably 10 to 40 mPa·s. Inkcompositions having a viscosity of 10 to 35 mPa·s are particularlypreferred.

Preference is given to ink compositions having a surface tension of15-73 mN/m, especially 20-65 mN/m, particularly preferably 30-50 mN/m.

Preference is given to ink compositions having a conductivity of 0.1-100mS/cm, especially 0.5-70 mS/cm, particularly preferably 1.0-60 mS/cm.

The inks may further include buffer substances, for example borax,borate or citrate. Examples are sodium borate, sodium tetraborate andsodium citrate.

They are used in particular in amounts of 0.1 to 3% by weight,preferably 0.1 to 1% by weight, based on the total weight of the ink, toset a pH of for example 5 to 9, especially 6 to 8. A citrate buffer ispreferred in the case of alginatic inks.

The inks may further include customary additives, for example foamsuppressants or especially fungal and/or bacterial growth inhibitors.These are customarily used in amounts of 0.01 to 1% by weight, based onthe total weight of the ink.

The printing inks and also the dye mixtures comprising comprising atleast the compound of formula (I) and at least one further compoundselected from the compounds of formula (II), (III), (IV) and/or (V).

The prints obtainable by the process of the invention have good generalfastnesses, a good lightfastness and also sharp contours and a highcolour strength. The inks provide prints of high optical density.

The printing inks used are notable for good stability and good viscosityproperties. The recording fluids of the invention have viscosity andsurface tension values which are within the ranges suitable for theink-jet processes. The viscosity remains virtually unchanged even in theevent of high shearing forces occurring during printing.

Recording fluids according to the invention in storage are not prone tothe formation of precipitates that leads to fuzzy prints or nozzlecloggage.

A further aspect of the present invention is the use of the printing inkin trichromatic printing. Trichromatic printing is a very largeapplication for all recording materials. This form of printing isnormally carried out with a yellow, red and blue ink composition.Furthermore, the magenta dye mixtures of the invention may be used as anink set in combination with black, yellow and/or cyan recording fluids.

The dyestuff mixtures according to the invention may be used for shadingother dystuffs or dyestuff mixtures. While the mixtures according to theinvention itself may be blended with other compabibles dyestuff mixturesto achieve the desired shade. Instead of blending the dystuff mixturesit is also possible to mix inks of different shades to achieve thedesired colour.

For example the shading colorant may be selected (among others) from thegroup consisting of C.I. Direct Red 1, 11, 37, 62, 75, 81, 87, 89, 95,227; C.I. Acid Red 115, 131, 144, 152, 186, 245, C.I. Pigment Red 122,176, 184, 185 and 269. The shading colorants are present in an amount of0.001 to 5% by weight, preferably 0.01 to 1% by weight, based on thetotal weight of the dry dye mixture.

This invention further provides recording materials, which have beenprinted with a composition according to the invention.

Moreover, the dye mixtures of the invention are useful as colorants inthe electrophotographic toners and developers, for example one- andtwo-component powder toners, magnetic toners, liquid toners,polymerization toners and other specialty toners.

Typical toner binders are addition polymerization, polyaddition andpolycondensation resins, such as styrene, styrene-acrylate,styrene-butadiene, acrylate, polyester, phenolic and epoxy resins,polysulfones, polyurethanes, individually or in combination, and alsopolyethylene and polypropylene, in or to which further ingredients, suchas charge control agents, waxes or flow agents, may be present or addedsubsequently. Dye mixtures according to the invention are further usefulas colorants in powders and powder coating materials, especiallytriboelectrically or electrostatically sprayed powder coating materials,which are used to coat the surfaces of articles made for example ofmetal, wood, plastic, glass, ceramic, concrete, textile material, paperor rubber. Powder coating resins employed are typically epoxy resins,carboxyl- and hydroxyl-containing polyester resins, polyurethane resinsand acrylic resins together with customary curing agents. Combinationsof resins are also used. For instance, epoxy resins are frequently usedin combination with carboxyl- and hydroxyl-containing polyester resins.

The dye mixtures of the invention are also useful as colorants for colorfilters, for additive as well as subtractive color generation (P.Gregory “Topics in Applied Chemistry: High Technology Applications ofOrganic Colorants” Plenum Press, New York 1991, page 15-25), and also ascolorants in electronic inks for electronic newspapers.

The examples hereinbelow illustrate the invention. Temperatures are indegrees Celsius; parts and percentages are by weight, unless otherwisestated.

Examples of Ink Compositions:

A preferred ink composition according to the invention comprises 0.5-35parts of a of formula (I), 65-99.5 parts of water or a medium includinga mixture of water and an organic solvent, an anhydrous organic solventor a solid having a low melting point and optionally 0-5 parts of one ormore additives.

A more preferred ink composition according to the invention comprises1-20 parts of a of formula (I), 80-99 parts of water or a mediumincluding a mixture of water and an organic solvent, an anhydrousorganic solvent or a solid having a low melting point and optionally 0-5parts of one or more additives.

A particularly preferred ink composition according to the inventioncomprises 1-5 parts of a of formula (I), 95-99 parts of water or amedium including a mixture of water and an organic solvent, an anhydrousorganic solvent or a solid having a low melting point and optionally 0-5parts of one or more additives.

A more preferred ink composition according to the invention comprises0.5-35 parts of a dye mixtures comprising at least one compound offormula (I) and at least one compound of formula (II), (III), (IV)and/or (V), 65-99.5 parts of water or a medium including a mixture ofwater and an organic solvent, an anhydrous organic solvent or a solidhaving a low melting point and optionally 0-5 parts of one or moreadditives.

A particularly preferred ink composition according to the inventioncomprises 1-2 parts of a dye mixtures comprising at least one compoundof formula (I) and at least one compound of formula (II), (III), (IV)and/or (V), 80-99 parts of water or a medium including a mixture ofwater and an organic solvent, an anhydrous organic solvent or a solidhaving a low melting point and optionally 0-5 parts of one or moreadditives.

A further preferred ink composition according to the invention comprises1-5 parts of a dye mixtures comprising at least one compound of formula(I) and at least one compound of formula (II), (III), (IV) and/or (V),and 95-99 parts of water or a medium including a mixture of water and anorganic solvent, an anhydrous organic solvent or a solid having a lowmelting point and optionally 0-5 parts of one or more additives.

The sum total of all the parts of the abovementioned compositionsaccording to the invention is 100 parts.

The abovementioned composition is preferably prepared by heating themedium to 40° C. and then adding a dye mixtures comprising at least onecompound of formula (Ie) and at least one compound of formula (II),(III), (IV) and/or (V), The composition is then cooled down to roomtemperature.

This ink composition is preferably used for printing papers or paperysubstrates.

The following Examples further serve to illustrate the invention,without restricting the scope of protection to these Examples. In theExamples all parts and all percentages are by weight, and thetemperatures given are in degrees Celsius, unless indicated to thecontrary.

EXAMPLE 1

a) Diazotization and Coupling

46 g (0.2 mol) 1-acetylamino-4-aminobenzene-3-sulfonic acid arediazotized indirectly in 300 ml water. The reaction solution is added toa suspension of 63,8 g (0,2 mol)2-amino-8-hydroxynaphthalin-3,6-disulfonic acid in 500 ml water at 5° C.The pH-value is adjusted to 2.5-4 by adding sodiumacetate-solution.After the termination of this reaction the compound of formula (I)

is filtered off.b) Isolation

The presscake of a) is washed with brine, until the filtrate becomesclear. After dissolving the presscake in demineralised water ofalkalinic pH and desalting by membran filtration, the concetratedsolution was dried and the residue milled to powder.

c) Formulation

The powder was dissolved in water at 20° C. to 40° C. and allingredients were added to obtain the following ink: 2.5 wt % of dyestuffI 15 wt % of N-methyl-2-pyrrolidone 82.5 wt % of water

The ink of example 1 comprising the dyestuff (I) was filtered bymicro-filtration (having 0.45 micrometer pores) and was ready to use forink jet printing.

The following formulations are used for printing materials as describedabove. Such compositions were made by the same procedure as described inexample 1) part c) but by using the dyestuff (I) previously purified bythe method of described in example 1) part c) and further ingredients asindicated in the following examples:

EXAMPLE 2

2.5 wt % of dyestuff I 15 wt % of diethylenglycol 82.5 wt % of water

EXAMPLE 3

2.5 wt % of dyestuff I 10 wt % of diethylenglycol 5 wt % ofN-methyl-2-pyrrolidone 82.5 wt % of water

EXAMPLE 4

2.5 wt % of dyestuff I 10 wt % of thiodiglycol 5 wt % ofN-methyl-2-pyrrolidone 82.5 wt % of water

EXAMPLE 5

2.5 wt % of dyestuff I 5 wt % of glycerol 5 wt % of diethylenglycol 2 wt% of triethanolamine 85.5 wt % of water

EXAMPLE 6

2.5 wt % of dyestuff I 10 wt % of diethylenglycol 1 wt % of Emulgen 6686.5 wt % of water

EXAMPLE 7

2.5 wt % of dyestuff I 10 wt % of diethylenglycol 3 wt % ofdiethylenglycol-mono-n-butylether 84.5 wt % of waterDyestuff Mixtures

90 wt-% of the compound of formula (I)

10 wt-% of C.I. Acid Red 52. The dyestuffs used were previouselypurified by desalting by membran filtration. The inks of the followingExamples 8 to 12 were made by the same procedure as described inexample 1) part c) but using the further ingredients as indicated in thefollowing examples:

EXAMPLE 8

2.5 wt-% of dyestuff Mixture 1 15 wt-% of N-methyl-2-pyrrolidone 82.5wt-% of water.

EXAMPLE 9

2.5 wt-% of dyestuff Mixture 1 20 wt-% of 1,2 propyleneglycol 77.5 wt-%of water.

EXAMPLE 10

2.5 wt % of dyestuff mixture 1 8 wt % of diethylenglycol 5 wt % ofglycerol 1 wt % of Emulgen 66 83.5 wt % of water

EXAMPLE 11

2.5 wt % of dyestuff mixture 1 5 wt % of diethylenglycolamine 5 wt % ofglycerol 87.5 wt % of water

EXAMPLE 12

2.5 wt % of dyestuff mixture 1 10 wt % of thiodiglycol 5 wt % ofdiethylenglycol 82.5 wt % of water

Purrified dyestuff were milled to powder mixed to the following ratiosas indicated in the dyestuff-mixtures 2-17. TABLE 1 (dyestuff-mixtures2-17) wt-% of wt-% of Mix. Compound 1 Compound 1 Compound 2 Compound 2 2Compound of 95 C.I. Acid Red 52 5 formula (I) 3 Compound of 80 C.I. AcidRed 52 20 formula (I) 4 Compound of 70 C.I. Acid Red 52 30 formula I 5Compound of 95 C.I. Acid Red 289 5 formula (I) 6 Compound of 80 C.I.Acid Red 289 20 formula (I) 7 Compound of 70 C.I. Acid Red 289 30formula (I) 8 Compound of 95 C.I. Acid Red 1 5 formula (I) 9 Compound of85 C.I. Acid Red 1 15 formula (I) 10 Compound of 95 C.I. Acid Red 60 5formula (I) 11 Compound of 85 C.I. Acid Red 60 15 formula (I) 12Compound of 95 C.I. Acid Red 30 5 formula (I) 13 Compound of 90 C.I.Acid Red 30 10 formula (I) 14 Compound of 80 C.I. Acid Red 30 20 formula(I) 15 Compound of 95 C.I. Acid Red 37 5 formula (I) 16 Compound of 90C.I. Acid Red 37 10 formula (I) 17 Compound of 80 C.I. Acid Red 37 20formula (I)

The inks of the following Examples 13 to 42 were made by the sameprocedure as described in example 1) part c) but using the furtheringredients as:

EXAMPLE 13

2.5 wt % of dyestuff mixture 2 10 wt % of diethylenglycol 5 wt % of1-propanol 82.5 wt % of water

EXAMPLE 14

2.5 wt % of dyestuff mixture 2 8 wt % of diethylenglycol 4 wt % ofdiethylenglycol-mono-n-butylether 3 wt % of 1-propanol 82.5 wt % ofwater

EXAMPLE 15

2.5 wt % of dyestuff mixture 2 10 wt % of ethylenglycol 5 wt % ofN-methyl-2-pyrrolidon 82.5 wt % of water

EXAMPLE 16

2.5 wt % of dyestuff mixture 3 15 wt % ofpolyethoxylated-(9)-triethanolamine 82.5 wt % of water

EXAMPLE 17

2.5 wt % of dyestuff mixture 3 15 wt % of diethylenglycol 82.5 wt % ofwater

EXAMPLE 18

2.5 wt % of dyestuff mixture 3 10 wt % of diethylenglycol 1 wt % ofEmulgen 66 86.5 wt % of water

EXAMPLE 19

2.5 wt % of dyestuff mixture 4 15 wt % ofpolyethoxylated-(6)-triethanolamine 82.5 wt % of water

EXAMPLE 20

2.5 wt % of dyestuff mixture 4 10 wt % of thiodiglycol 5 wt % ofdiethylenglycol 82.5 wt % of water

EXAMPLE 21

2.5 wt % of dyestuff mixture 4 10 wt % of triethylenglycol 5 wt % of1-propanol 82.5 wt % of water

EXAMPLE 22

2.5 wt % of dyestuff mixture 4 10 wt % of 1,5-pentanediol 5 wt % ofdiethylenglycol 82.5 wt % of water

EXAMPLE 23

2.5 wt % of dyestuff mixture 5 15 wt % of2-[2-(2-methoxyethoxy)ethoxy]-ethanol 82.5 wt % of water

EXAMPLE 24

 2.5 wt % of dyestuff mixture 5   15 wt % ofN-(2-hydroxy)ethyl-2-pyrrolidon 82.5 wt % of water

EXAMPLE 25

 2.5 wt % of dyestuff mixture 5   10 wt % of 2-diethylamino-1-ethanol  5 wt % of o,o-bis-(2-aminopropyl)-polyethylenglycol 500 82.5 wt % ofwater

EXAMPLE 26

 2.5 wt % of dyestuff mixture 6   15 wt % of diethylenglycol 82.5 wt %of water

EXAMPLE 27

 2.5 wt % of dyestuff mixture 6   10 wt % of N-ethyl-2-pyrrolidone   3wt % of triethanolamine 84.5 wt % of water

EXAMPLE 28

 2.5 wt % of dyestuff mixture 6   10 wt % ofo-(2-aminoethyl)-polyethylenglycol 750   5 wt % of thiodiglycol 82.5 wt% of water

EXAMPLE 29

 2.5 wt % of dyestuff mixture 6   10 wt % of 3-dimethylamine-1-propanol  5 wt % of glycerol 82.5 wt % of water

EXAMPLE 30

 2.5 wt % of dyestuff mixture 7   10 wt % of N-methyl-2-pyrrolidon   1wt % of Emulgen 66 86.5 wt % of water

EXAMPLE 31

 2.5 wt % of dyestuff mixture 7   10 wt % of diethylenglycol   1 wt % ofEmulgen 66 86.5 wt % of water

EXAMPLE 32

 2.5 wt % of dyestuff mixture 7   10 wt % of diethylenglycol   5 wt % ofcyclohexanol 82.5 wt % of water

EXAMPLE 33

 2.5 wt % of dyestuff mixture 8   10 wt % of diethylenglycol   5 wt % ofpolyoxyethylen-(9)-triethanolamin 82.5 wt % of water

EXAMPLE 34

 2.5 wt % of dyestuff mixture 9   10 wt % of 1,5-pentanediol   5 wt % ofglycerol 82.5 wt % of water

EXAMPLE 35

 2.5 wt % of dyestuff mixture 10   10 wt % of triethanolamine   1 wt %of Emulgen 66 86.5 wt % of water

EXAMPLE 36

 2.5 wt % of dyestuff mixture 11   10 wt % of diethylenglycol   5 wt %of o,o-bis-(3-aminopropyl)-polyethylenglycol 1500 82.5 wt % of water

EXAMPLE 37

 2.5 wt % of dyestuff mixture 12   10 wt % ofPolyoxyethylen-(6)-triethanolamine   5 wt % of 1-Propanol 82.5 wt % ofwater

EXAMPLE 38

 2.5 wt % of dyestuff mixture 13   15 wt % of diethylenglycol 82.5 wt %of water

EXAMPLE 39

 2.5 wt % of dyestuff mixture 14   10 wt % of diethylenglycol   1 wt %of Emulgen 66 86.5 wt % of water

EXAMPLE 40

 2.5 wt % of dyestuff mixture 15   15 wt % of 3-diethylamine-1-propanol82.5 wt % of water

EXAMPLE 41

 2.5 wt % of dyestuff mixture 16   10 wt % of thiodiglycol   5 wt % ofdiethylenglycol 82.5 wt % of water

EXAMPLE 42

 2.5 wt % of dyestuff mixture 17   10 wt % of2-(2-diethylaminoethoxy)-ethanol   5 wt % of diethylenglycol 82.5 wt %of water

APPLICATION EXAMPLES

An ink as indicated above was introduced into an HP 880C DeskJet Printerand printed onto an A4 HP Premium Inkjet paper (HP and DeskJet areregistered trademarks of Hewlett-Packard, Palo Alto, Calif., USA).Different properties of the prints have been tested which results arelisted next to the ink compositions (Table 2). In the last coloum (withthe asterix ^((*))) the difference of the resulting shade when printedis given relative to the Application Examples A-I to A-III which aremagenta. TABLE 2 (Application examples A-I to A-XXVII) Ink- differenceApplication Example preparation lightfastness brilliance waterfastnessof shade^((*)) A-I Example 1 excellent excellent very good A-II Example2 excellent excellent very good A-III Example 6 excellent excellent verygood A-IV Example 8 very good excellent very good more bluish A-VExample 10 very good excellent very good more bluish A-VI Example 13excellent excellent very good more bluish A-VII Example 15 excellentexcellent very good more bluish A-VIII Example 16 good excellent verygood more bluish A-IX Example 18 good excellent very good more bluishA-X Example 19 moderate excellent very good more bluish A-XI Example 20moderate excellent very good more bluish A-XII Example 23 excellentexcellent very good more bluish A-XIII Example 24 excellent excellentvery good more bluish A-XIV Example 28 good excellent very good morebluish A-XV Example 29 good excellent very good more bluish A-XVIExample 30 moderate excellent very good more bluish A-XVII Example 32moderate excellent very good more bluish A-XVIII Example 33 excellentgood very good more bluish A-XIX Example 34 very good good very goodmore bluish A-XX Example 35 very good good very good more bluish A-XXIExample 36 good good very good more bluish A-XXII Example 37 very goodgood very good more yellowish A-XXIII Example 38 very good good verygood more yellowish A-XXIV Example 39 very good good very good moreyellowish A-XXV Example 40 excellent good very good more yellowishA-XXVI Example 41 excellent good very good more yellowish A-XXVIIExample 42 excellent good very good more yellowish

1. A dyestuff mixture comprising at least compound of formula (I)

as free acid or in salt form and at least one compound selected from thegroup consisting of formula (II), formula (III), formula (IV), andformula (V) wherein the compound of formula (II) is

wherein R₇ and R′₇ are independently from each other H or halogen, R₈ is—OH or NR₁₆R₁₇, wherein R₁₆ is H; unsubstituted C₁₋₄alkyl; substitutedC₁₋₄alkyl; unsubstituted phenyl or a substituted phenyl, R₁₇ isunsubstituted C₁₋₄alkyl; substituted C₁₋₄alkyl; unsubstituted phenyl ora substituted phenyl, R₉ is O or NR₁₇, wherein R₁₇ has the same meaningas defined above, R₁₀ and R′₁₀ are independently from each other H;halogen; unsubstituted C₁₋₂alkyl or —NO₂, R₁₁ is —SO₃H or —COOH, R₁₂ isH or halogen, R₁₃ is H; —SO₃H or halogen R₁₄ is H or halogen, R₁₅ is Hor halogen, wherein the compound of formula (II) is

wherein

R₁₈ is H; —COC₁₋₂alkyl; —CO(CH₂O)_(n)—R₂₂; or —SO₂R₂₂, wherein R₂₂ is anunsubstituted phenyl or a phenyl moiety, which is substituted by atleast one substituent selected from the group consisting of —CH₃ andhalogen, n is 0 or 1, R₁₉ is H; —CH₃; —SO₃H or —OR₂₃, wherein R₂₃ is—CH₃; unsubstituted phenyl; substituted phenyl or benzyl R₂₀ is H;halogen; C₁₋₁₀alkyl or —NHCOCHBrCH₂Br R₂₁ is H; —NO₂; C₁₋₁₅alkyl orC₅₋₇cycloalkyl; wherein the compound of formula (IV) is

wherein R₂₄ is H or —SO₃H, R₂₅ is H; —NHCOC₁₋₂alkyl or —OH, R₂₆ is H or—OH R₂₇ is

wherein R₂₈ is H or unsubstituted phenyl, R₂₉ is H; —COH; —NO₂;

wherein R₃₀ is H or —CH₃, or R₂₇ is

wherein the compound of formula (V) is

wherein R₃₁ is H or

R₃₂ is

wherein R₃₃ is H; —SO₃H; —CF₃; —Cl; —COOC₁₋₂alkyl; or —SO₂R₃₆, whereinR₃₆ is unsubstituted phenyl; substituted phenyl; O-phenyl;—NH—C₁₋₁₂alkyl; —N(C₁₋₆alkyl)₂; unsubstituted C₅₋₈cycloalkyl;substituted C₅₋₈cycloalkyl; C₅₋₈cycloalkyl with at least one N, O or Satom incorporated into the ring;

R₃₄ signifies is H; —NHCOC₁₋₄alkyl; —NHCOphenyl, wherein the phenyl ringis unsubstituted or substituted; —N(C₁₋₂alkyl)COC₁₋₄alkyl;—N(C₁₋₂alkyl)COphenyl, wherein the phenyl ring is unsubstituted orsubstituted; unsubstituted phenyl; substituted phenyl; O-phenyl, whereinthe phenyl is unsubstituted or substituted; halogen; —SO₃H;—NHCOOC₁₋₂alkyl; —NHCOOC₅₋₇cycloalkyl, wherein the cycloalkyl issubstituted or unsubstituted and —SO₂NHphenyl, wherein the phenyl ringis unsubstituted or substituted, R₃₅ is H; —NHCOC₁₋₄alkyl; —NHCOphenyl,wherein the phenyl ring is unsubstituted or substituted;—N(C₁₋₂alkyl)COC₁₋₄alkyl; —N(C₁₋₂alkyl)COphenyl, wherein the phenyl ringis unsubstituted or substituted; unsubstituted phenyl; substitutedphenyl; O-phenyl, wherein the phenyl is unsubstituted or substituted;halogen; —Cl; —CH₃; —COOC₁₋₄alkyl and —SO₂NHphenyl, wherein the phenylring is unsubstituted or substituted.
 2. The composition according toclaim 1 wherein the compound according to formula (II) is selected fromthe grout consisting of C.I. (Colour Index) Acid Red 50, C.I. Acid Red51, C.I. Acid Red 52, C.I. Acid Red 87, C.I. Acid Red 91, C.I. Acid Red92, C.I. Acid Red 93, C.I. Acid Red 94, C.I. Acid Red 95, C.I. Acid Red98, C.I. Acid Red 289 Acid Violet 9 and C.I. Acid Violet
 30. 3. Thecomposition according to claim 1, wherein the compound of formula (II)is Acid Red 52 or C.I. Acid Red
 289. 4. A recording fluid comprising adye mixture according to claim
 1. 5. A recording fluid as claimed inclaim 4, wherein the dye mixture is in desalted form.
 6. A recordingfluid as claimed in claim 4, wherein the recording fluid is an ink-jetink.
 7. A recording fluid according to claim 4, further comprising wateror a medium including a mixture of water and an organic solvent, ananhydrous organic solvent or a solid having a low melting point.
 8. Anelectrophotographic toner comprising a dyestuff mixture according toclaim
 1. 9. A method for dyeing or printing natural or synthetic fibermaterials, for recording script and images on recording media, or forcoloring paper or cellulose in the pulp, comprising the step of adding adye mixture according to the claim 1 to said fiber material, recordingmedia or pulp.
 10. An inkjet printing composition for printing recordingmaterials comprising 1) the dye of formula (I)

and 2) water or a medium including a mixture of water and an organicsolvent, an anhydrous organic solvent or a solid having a low meltingpoint,
 11. A printing method for printing a substrate with a Printingink comprising the step of adding to the printing ink Use of a compoundof formula (I)


12. The composition according to claim 1 wherein the compound accordingto formula (III) is selected from the group consisting of C.I. Acid Red1, C.I. Acid Red 33, C.I. Acid Red 35, C.I. Acid Red 40, C.I. Acid Red76, C.I. Acid Red 106, C.I. Acid Red 138, C.I. Acid Red 0.155, C.I. AcidRed 160, C.I. Acid Red 172, C.I. Acid Red 249, C.I. Acid Red 264 andC.I. Acid Red
 265. 13. The composition according to claim 1 wherein thecompound according to formula (IV) is selected from the group consistingof C.I. Acid Red 15, C.I. Acid Red 19, C.I. Acid Red 29, C.I. Acid Red60, C.I. Acid Red 68, C.I. Acid Red 154 and C.I. Acid Red
 176. 14. Thecomposition according to claim 1, wherein the compound according toformula (V) is selected from the group consisting of C.I. Acid Red 30,C.I. Acid Red 34, C.I. Acid Red 37, C.I. Acid Red 42, C.I. Acid Red 54,C.I. Acid Red 57, C.I. Acid Red 231, C.I. Acid Red 266, C.I. Acid Red301 and C.I. Acid Red
 337. 15. The method of claim 11, wherein theprinting method is ink jet printing or electrophotographic printing.